The sides of a wound during surgery are inherently susceptible to bacterial infection if touched by contaminated substances such as diseased body parts and fluids as they pass through the wound. Therefore extreme care must be exercised to insure that the exposed sides of an incision are completely covered by a material impervious to solids and fluids containing bacteria and other contaminants before surgery proceeds.
Various techniques have been used to insulate any incised tissue from exposure. One form of protection for relatively large incisions typically employs soft cotton sponges held against the sides of the wound by metal retractors to minimize contamination as well as to give the surgeon better access into the operating site. Another form of wound protector, particularly suitable for minimally invasive surgery, is disclosed in U.S. Pat. No. 3,347,227 to Harrower. It is constructed of a thin transparent and flexible sheet of material, impervious to bacteria and fluids, which is formed into a sleeve and secured at opposite ends to a pair of preformed resilient rings. One ring is squeezed into an oblong shape, inserted through the cavity wall, and allowed to expand to the preformed shape over the inside edge of the wound. The other ring overlaps the outside edge causing the sleeve to stretch into contiguous contact with the entire surface of the sides and inner and outer edges of the wound. To obtain a form-fitting contiguous contact with the sides of the wound, the circumference of both rings in their preformed shape must be slightly larger than that of the incision, and the extended length of the sleeve between the rings slightly greater than that of the wall thickness. To accommodate variations in wound sizes, this entails manufacturing and provisioning wound protectors in numerous combinations and permutations of both circumferences and lengths. U.S. Pat. No. 3,347,226 to Harrower describes an adjustable wound protector which reduces, to a degree, the number of sizes required. It requires a number of predetermined lengths similar to U.S. Pat. No. 3,347,227 supra, except the circumference of the wound protector is adjustable, before being installed in the wound, by the rings having telescoping ends, and the side of the sleeve having overlapping lengthwise edges. Any overlapping excess may be cut off. The rings have a maximum adjustable circumference slightly larger than that of the largest incision anticipated so that they are sure to overlap the inner and outer edges of the wound. However, a sleeve length must be selected which will closely conform to the wall thickness at the wound. Consequently, to insure a precise form fit for different size wounds, it is still necessary to provide numerous combinations of sleeve lengths and ring maximum adjustable circumferences.